Better maps changed the story about which rivers carry plastic to the sea

Earlier studies suggested a handful of large rivers carried most river-borne plastic into the ocean. A higher-resolution model instead found a much larger contribution from numerous smaller waterways.

The revised approach considered how waste reaches a river and then the sea: proximity, rainfall, wind, terrain, and river flow all matter. A large inland population does not automatically produce the same marine pollution as a smaller population close to a coastal outlet.

The estimates retain substantial uncertainty, and river inputs are not the whole ocean-plastic problem; fishing equipment and other marine sources also contribute. But the modeling change has a direct policy implication. A strategy concentrated on a few famous rivers can miss many relevant entry points. Better spatial detail changes where limited prevention resources might be useful.